Conventionally, as a uniaxial eccentric screw pump, there has been known a uniaxial eccentric screw pump having the configuration where a stator is formed of a stator body and an outer sleeve, and the outer sleeve can be easily split from the stator body (see Japanese Unexamined Patent Application Publication No. 2012-137038, for example).
In such a conventional uniaxial eccentric screw pump, there may be a case where an internal surface of the stator body is cleaned and sterilized simultaneously with the supply of a high-temperature fluid such as vapor or hot water into the stator body. In this case, the stator body expands. However, the deformation of the stator body toward an outer diameter side is prevented by the outer sleeve and hence, a displacement amount toward an inner diameter side, that is, interference (overlapping between an outer surface of a rotor and an inner surface of the stator) is increased. When the rotor is rotated in such a state, a frictional force of the rotor against the stator body becomes excessively large and hence, there may be a case where an abnormal wear occurs on the stator body or the rotor is damaged. Further, there may be also a possibility that the rotor cannot be rotated. Accordingly, interference is adjusted by disposing a shim between the stator body and the outer sleeve.
However, such an interference adjusting operation is a complicated and cumbersome operation which must be performed manually. Further, it is necessary to perform the interference adjusting operation each time an operation mode (a normal operation and a cleaning operation) is switched. Accordingly, there has been a demand for the improvement of the interference adjusting operation.